Bushing terminal



Dec, l, u1931. G. A. BURR ET AL 1,834,379

BUSHING TERMNAL FlecbkmV 18. 1929 Fig. 2.

Gordon ABZ/rr l, JosBeYph HSG/Brumm.

Patented Decl.`1,` 1931 d i UNITED STATES" PATENT- GORDON Alarma; oF WILKINSBURQAND .rosier-1111H. scHnAMir.onirlr'rsnrmeif cui Vand particularlyto terminals for the PENNSYLVANIA, AssrGNoas 'ro wEsTINGHoU's'E t y COMPANY; A loo'moRA'rIoN oFprE'NNsYLvANIA BUSHING TERMINAL Application mea Janary 1s, 1929.*seria1 Nc. 333,468(

Ourinvention relates tobushing terminals l outer ends of high-voltage bushings.

` One'. object of our invention is to provide a bushing of the above-indicated character that shall be readily employed interchangeably in applications requiring, or desirably utilizing, vthrough conductorsk of different kindsw c,

Another object` of our invention is to compensate for. discrepancies sometimes occurring between the relative lengths of bushings andy through conductors therefor.

Another object of our invention is to provide a bushing whichfmaybe removed from` serviceposition for repair *or replacement without detaching the through conductor.

, thereof `at its,4 inner end and which shall facilitate the introduction of the through conf ductor to a bushing when the latter isv being placed in position.,

Anotherobject of our inventionv is to provide a bushingtliat shall prevent breathing andthe entrance of oilor other luidinsulatingmedium into the bushing from a receptacle with which Ait cooperates.

Another object o'fourinvention is to facilitate the assembly andrepair of the bushing and its associated apparatus;

'A further object of our invention is to pro-y vide abushing structure that shall be simple and durable in construction, economical to manufacture and effective in its operation.

In certain bushing practice, especially that wherein relatively high voltages are employed, and wherein relatively long tubular refractory or porcelain elements are employed, the refractoryy `elements sometimes vary in length as much as siX` percent. This variation 'is caused by shrinkage effects in the ceramic material during tiring, v as is wellknowinl f By reason of the-fact that the :refractory elements have definite shapes at the ends thereof for the reception ofterminal members,'they`l`cannot be'cut ovto 'renderthem `of uniform lengths and, consequently, `other means must belemployed to compensatefor the'diflerences. -k t Also,y in bushingsA having ELECTRIQ ANn'MM'ANurAc'rUaING A ings which communicate,` the interiors il oftanksor casings of electrical apparatus, there is sometimes a breathing or otherl ef-I feet, .caused Vby yheating and the. expulsion ferent relative lengths of the connectors and f the bushings, through which the conductors are to extend,toprevent the aboyegmentioned breathing, to" permit a bushingl to` be.` readily adapted, with only slight change, yfor. oper-` ation in connection with different apparatus and to otherwisedesirably improvev the structure.'

, Accordingly, in practicing our, invention,

.we provide a bushing v,embodying a tubular Y,

refractory element, atubular through conductor, a sealing cap for the tubular through conductorand` a .combined terminal and adjusting -means for a flexible through conductor to accomplish the. purposes of--our invention.

, vFigure 1- ofthe accompanying drawings :is i

'a side elevational yView of a bushing constructed inaccordancelwith our invention;V Fig. 2 is an enlarged view, taken along the line II-II of Fig- 3, and f .c Fig; 3 isan enlarged'longitudinalvsectional view of the upper end ofthestructureshown in Fig. 1j.A

The device comprises, inl general, acondenser-bushingelement 2,-means3 at anY intermediate portion thereof4 for f securing lthe sameto a tankor casing withwwhich the bushingE is to cooperate, a tubular refractory weather-protective member 4, an upper teryininal structure 5 and a' lower end member 6.

The bushing structure 2 is of; a usual welll known condenser type comprising a plurality Vof dip-electric layers Sbetween` vwhich are dis- H10ov f posed conducting layers (not shown) of material such as tin, lead or aluminum foil. In this structure, which is disposed about a cen tral tubular conductor 9, as shown in Fig. 3, the conducting and cli-electric layers are of successively outwardly greater diameters and shorter lengths to provide nearly equal capacity between the condenser elements.

` The outer 'or weather-exposed portion of the bushing element 2 is protected by the refractory or porcelain member 4 which is preferably constructed in one piece andV provided with a plurality of surface-creepage flanges or petticoats 12. The member 4 is secured to the structure 3 in any suitable manner, not germane to this invention, whereby the bushing isheld in position in an opening in a tank cover (not shown).

The upper terminal structure 5, las shown more clearly in Figs'. 2 and 3, comprises a ring 14, of substantially L-shape in crossseetion, having one arm or flange secured to the outer end of the member 4, as by a body of cement, 4alloy or other suitable medium 15. The other arm of the element 14 is provided with openings for the reception of screws 16 which extend into a weatherl casing element 18. A sealing gasket 19 is clamped in position by the screws l'between the members 4 and 18. Y

The weather casing 18further comprises an inner flange 21, a plurality of tapped openings 22 and portions 23 for the reception of lifting eyes 24.V Athrust nut 25 is mounted on the tubular conductor 9 and so cooperates with the flange 21 that, when the bushing is lifted by means kof the eyes 24, the weight of the bushing is placed on the tube 9 and not on the sealing medium 15.

A terminal element at the upper end of the tubular conductor y9 comprises a vscrewthreaded sleeve portion 27 and a box or receptacle-like portion 28 having an inner opening 29 and a terminal-receiving portion 30. A cover 32 is secured to the portion`28 by screws 34 which compress a sealing gasket 35 between the members 28 and 32.

An outer lcap member 37 is provided with peripheral openings for the reception of screws 39 which secure the sameto the weather casing 18. The cap 37 is also provided with a screw threaded outer terminal stud 40 and a tapped opening 41 adjacent thereto. A conductor 42 is connected between the cap member' 37 and the portion 28 by screws 44 and 45, respectively.

\' The structure, as described so far, may be employed as a bushing for a circuit interrupter wherein a stationary contact terminal (not shown) is employed as a `substitute for, or as an addition to, the lower member 6,`as Vindicated in Fig. 1. In this case, the tube 9 constitutes the through conductor.

`Hcwever,'when the bushing is togbeem- 5 'ployed in connection with 'a transformer or other apparatus having terminals remotely disposed with respect to the lower member 6, it is desirable to employ a flexible conductor 46, as indicated in Figs. 1 and 3, extending through the tubular conductor 9.

In the latter application, itis desirable to have the flexible conductors 46, of similar bushings, of the same length and to provide them with ends, such as an end 48 shown in Fig. 3, which cooperate with, and are secured to, terminal portions similar to the terminal portion 40, as by screws `50, the lower ends being extended directly to the transformer coils or other apparatus of which they may constitute permanent parts.

Since, as hereinbefore stated, the refractory member 4 varies considerably in length in different bushings, the flexible conductor 46, to be of a fixed length, must be of sufli cient length to extend from its inner end (not shown) to the terminal portion 40 in the longest bushing. Hence, when it is employed with a bushing employing a shorter member 4, the conductor 46 is longer than necessary and will be in a slack condition unless compensated for, as by our invention.

To eliminate this slack, the flexible conductor 4G is drawn taut through the tubular conductor 9 and through the opening 29 and clamped in taut condition by a cam clamping member 52 that is pivotally mounted on a portion 53 of the portion 28 and held in position by a nut-and-bolt device 54.

r In the above described structure, when employed, as a transformer bushing, the flexible conductor 46 may be readily lished up through the tubular conductor 9 and secured in position, as illustrated in Fig. 3. The elements 28 and 32, together with the sealing gasket- 35, constitute a hermetically-tightA sealing means to prevent breathing and the passage of oil into or through the tubular conductor 9. When it is desired to utilize the bushing as a circuit-interrupter terminal, the flexible lead 4G may be omitted and the tube 9 still be hermetirally sealed, as above described.

l/Vhile we have shown and described a particular form of our invention, changes may be effected therein without departing from the spirit and scope thereof, as set forth in the appended claims.

7e claim our invention:

1. In combination, a bushing, a tubular conductor extending therethrough, a flexible conductor extending through said tubular conductor and means on said tubular conductor for eliminating slack in said flexible conductor.

2. In combination, a bushing, a tubular vconductor therein, a cap for the tubular conductor comprising a terminal member on the conductor and a cover memberl for the terminal member, a flexible conductor in the tubular conductor. .secured to ,said` terminal electrically connected to said terminal member.

3. In combination, a tubular bushing element, a tubular conducting element extending therethrough, a flexible conductor extending through said tubular conductor, and an end-closure member for one of said elements,

including means for holding said flexiblel conductor after slack has been taken up therein. y

4. In combination, a bushing, a terminal, a flexible conductor having a portion in the bushing and an end secured to said terminal, and means for tensioning the conductor including means for holding a buckled portion of the conductor between the holding means and said terminal. f y

y5. In combination, a bushing, a flexible conductor having a portion therein, and means supported by the bushing and adjustable laterally to the conductor for holding a portion of the conductor in buckled form to eliminate. slack in the conductor.

6. In combination, a bushing, a flexible conductor having aportion therein, and camclamping means acting laterally to the conductor for holding the conductor after slack has been taken up therein. i

7. In combination, aV bushing, a flexible conductor having a portion therein, an endclosure element for the bushing, and means associated with said element and adjustable laterally to the conductor for holding the conductor after slack has been taken fup therein. j

` 8. In combination, a bushing, a flexible conductor having a portion therein, said conductor having an end terminal portion, a cooperating terminal portion carried by theI bushing, and means for holding another portion of the conductor in buckled form to eliminate slack in the conductor.

9. In combination, a bushing, a flexible conductor having a portion therein, said conductor having an end terminal ortion, a

' co-operating terminal portion carried by the bushing, and means also carried by the bushing adjacent to said (zo-operating terminal portion for holding another portion of the conductor in buckled form to eliminate slack in the conductor.

- 10. In combination, a bushin a lflexible conductor having a portion therein, a tubular Y conductor surrounding the flexible conductor in the bushing, and means on the tubular conductor for holding the flexible conductor after slack has been taken up therein.

11. In combination, a bushing, a flexible conductor having a portion therein, a tubular conductor surrounding the flexible conductor in the bushing, end-closure means for the tubular conductor, and means associated with said end-closure means for holding the con-V ductor after slack has been'taken up therein.

12. In combination, a bushing, a flexible lar conductor, means for conductivel'y connecting said caps, terminal means in the tubular-conductor cap for the flexible conductor, and means in the tubular-conductor cap for holding the flexible conductor after slack has been taken up therein.

13. In combination, a conductor, a bushing surrounding the same and secured thereto, an end structure for the bushing including means whereby the bushing may be lifted, means for securing'said end structure to the bushing, and means co-operating between the end structurey and the conductor for transmitting the lifting forces to the conductor and thereby relieving said securing means of said forces.

14. In combination, a conductor, a bushing surrounding the same and secured thereto, an end structure for the bushing including means whereby the bushing may be lifted and having an innershoulder, means for securing said end structure to the bushing, and a f I thrust nut on the conductor co-operating with said shoulder for transmitting the lifting forces from the end structure to the conductor and thereby relieving the securing means of said forces. Y 4

` 15. In combination, in a bushing, a dielectric tube, a metal tube securedin position therein and having a screw-threaded portion projecting from oneend thereof, a metal collar surrounding, and secured to, said end of the dielectric tube, an element surrounding Vsaid projecting portion over the transverse ary, 1929.

GORDON? A. BURR. JOSEPH II. SCHRAMM. 

